Numerous planets have one or more species of animal (native or immigrated) that can get very big, but I don’t know of any where that’s a defining characteristic of the lifeforms there. Like Earth, most planets have megafauna as well as smaller species, and many have ones that are dinosaur-sized (although I suppose it depends on which dinosaur…)
One of the best examples might be Tatooine, with a number of massive species such as banthas, dewbacks, rontos, sarlaccs, rancors (rare on Tatooine) and krayt dragons. You will also find large animals on pretty much any jungle world; Dagobah has giant swamp slugs and dragonsnakes, Endor has gorax and boar-wolves, Yavin 4 has runyips. Also worth noting would be Bespin, home to absolutely huge animals such as the beldon (which can grow up to 10km in diameter) and the velker, and Naboo, with giant aquatic animals as well as mammals such as falumpasets and fambaas. Basically, you’re likely to find something big on just about any planet.
I hope one of those works!
~ Jacen









